1. Field of the Invention
This invention relates to a page re-ranking system and a page re-ranking program that grants a renewed page ranking to a Web page that is obtained as a search result page and to which a page ranking is given
2. Description of Related Art
Recently a search service has been known that rapidly extracts and outputs a corrected search result from a flood of information on the Web in compliance with a query. In order to make it possible to utilize the search result more effectively, a technology has been proposed that gives a page ranking as being an evaluation index showing its usability to a Web page obtained as a search result page.
An outline of a technology that creates this kind of a page ranking will be explained.
For example, a link from a Web page A to a Web page B is considered to be a supporting vote to the Web page B by the Web page A and an indication of the importance of the Web page B is judged to be based on the number of the supporting votes. At this time, not only the number of the supporting votes, namely a number of links to the Web page but also the Web page that casts the supporting vote is analyzed. Then the supporting vote cast by a Web page whose “level of importance” is ranked high is more highly evaluated and the Web page that receives the supporting vote is set to be “an important page.”
It is so arranged that the important page that receives a high evaluation by this link analysis is also given a high page ranking and its final ranking in the search results becomes high. Examples of this type of re-ranking system can be found at (1) “Google no ninnki no himitsu (Secret of Google's popularity)” http://www.google.co.jp/intl/ja/why_use.html, (2) “Google Searches More Sites More Quickly, Delivering the Most Relevant Results” http://www.google.com/technology/index.html and (3) “Benefits of Google Search” http://www.google.com/technology/whyuse.html.
There is still a need to improve the ability to search for relevant information on the Internet and other large data bases and to prioritize the results: